Coffee filter



FIG. 1 is a top perspective view of a coffee filter showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a side elevational view thereof, the opposite side being a duplicate;

FIG. 4 is an end elevational view thereof, the opposite end being a duplicate; and

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a coffee filter, as shown and described. 